Technologies devoted to the manufacture of electronics and electronic devices from memory devices to microprocessors to computers and cellular phones have seen significant advances. Where most electronic devices are now manufactured in a mass production setting, quality assurance of the manufacturing process plays a vital role in reducing the yield loss in a production process as well as assuring that the number of defective devices released to the public consumer is minimized. While the technologies related to the manufacturing of electronics and electronic devices have seen significant advances, technologies related to the quality assurance and quality checking of such devices have remained somewhat antiquated.
In the electronics industry, a standard quality checking procedure known as the dye-and-pry technique is employed to identify if small cracks or other surface defects have developed in the electronic components themselves as well as solder joints between electronic components. The dye penetrant (dye-and-pry) technique requires first applying a dye to the electronic devices under scrutiny. Samples for the dye impregnation undergo a process that includes, for example: (1) remove flux; (2) immerse sample in Dykem red steel layout fluid; (3) subject the device to a vacuum for 10 minutes (perform this process three times to ensure the dye penetration); (4) remove from vacuum and drip-dry under chemical hood for at least 30 minutes; (5) bake sample for about 30 minutes to remove any residual solvents; and (6) remove samples from the oven and allow to cool to room temperature. The next stage of the process requires carefully prying the electronic devices away from their fixed position on the sample.
After the electronic device has been pried apart from its position, the former electronic connections can be inspected to see if the dye penetrated any surface of the electronic devices or their joints. The existence of dye on an inner surface of the electronic device is an indication that a fault existed prior to prying the electronic device away from its position.
Unfortunately, the dye-and-pry technique is a time consuming and destructive technique that requires the prying of components (e.g., microprocessors, memory devices, and other types of integrated circuits (ICs)), physically and mechanically, away from their respective electronic devices (e.g., a circuit board for a phone, cellular phone, personal digital assistant (PDA), remote email retrieval device, computer, laptop, and so on). Therefore, the dye-and-pry technique makes the location of the origin of the crack almost impossible because it is difficult to distinguish whether the crack developed during the manufacturing of the product or during the prying. Since it is difficult to detect where a crack or surface defect originated, it becomes more difficult to identify the step in the manufacturing process that might have caused the defect. Furthermore, this type of post hoc analysis cannot be used as a quality assurance tool for all products destined for market, because such an analysis results in the destruction of the product. Rather, the dye-and-pry technique can be applied only to a small number of electronic devices that are presumably representative of their entire batch of products.
X-ray examination techniques have also been employed to inspect the quality of electronic devices. However, current X-ray examination techniques are not very useful because traditional X-ray images do not readily show where a defect is located or if a defect exists at all. Furthermore, nano-scale defects may not even be detectable using traditional X-ray examination techniques.